Electric heater



March 4, 1952 G. c. WICKS ELECTRIC HEATER 3 Sheets-Sheet 1 Filed Oct.16, 1947 GERALD 6. W/C/(S INVENTOR.

7 m %QLLMSJ HTTORNE March 4, 1952 G. c. WICKS ELECTRIC HEATER 3Sheets-Sheet 2 Filed Oct. 16, 1947 14 TTOR/V E Y ELECTRIC HEATER FiledOct. 16, 1947- 3 Sheets-Sheet 5 652M063 W/C/(S JNVENTOR.

f? TTOQN E Y Patented Mar. 4, 1952 UNITED STATES PATENT OFFICE ELECTRICHEATER Gerald G. Wicks, New York, N. Y. Application October 16, 1947,Serial No. 780,229

9 Claims.

This invention relates to electric heaters but more specifically toautomatically operable and attachment type of heaters secnrable to fluidsources such as faucets and is an improvement over my U. s. Patent No.2,400,618 dated May 21, 1946, and :U. S. patent application Serial No.641,911 efiled January .18, 1946, now Patent No. 2,471,133, dated May24, 1949.

l Heretofore in attachment types of electric heaters eitherelectrolytically operated or operated by passing a current through anelectric heating element in direct contact with the Water in a waterheatingcompartment, derivative currents in the water have been found tobe communicated (both or either to the water source and the dischargedhot water from the device giving rise to serious objections to the useof heaters of this type.

The present invention covers an attachment type of heater havinginternal inlet and outlet channels to and from another water compartemcnt, id c mpartm nt and ch ne s bein formed from a pair'of opposed andsimilar blocks of dielectric material. The inlet and outlet channels areadapted to be independently in-v sulated and are of such dimensions asto give the water or fluid flow therethrough suflicient electricalresistance for service as effective resistors so that objectionableeffects such as shocks are not communicated to the water source and tothe discharged heated water.

A feature of the invention resides in the pro-. vision of internal inletand outlet insulated channels in communication with a water heatingcompartment all forming part of a casing of dielectric material whereinthe said channels are of such dimensions as to give the fluid flowtherethrough resistor properties. Incidental to this feature is theprovision of a pair of spaced electrodes mounted in the fluid path toserve as a means for controlling the energization of an electric heatingelement in direct contact with the water in the water heatingcompartment.

Another feature of the invention resides in the provision of a pressureswitch in series circuit relation with the spaced electrodes to controlthe .energization of the electric heating means in the water heatingcompartment during fiuid flow, the said switch being responsive to fluidpress re w th n the .fiuid path of the evic A further feature r sides inthe provision of an electric heater wherein the degree of temperature ofthe discharged water is controllable by the degree f opening of thefluid source valve.

These bjects a d other incidental ends and advantages of the inventionwill hereinafter appear in the progress of the disclosure and as pointed:out in the appended claims.

Accompanying this specification are drawings showing a preferred form ofthe invention wherein:

Figure 1 is a view in perspective of the heater in actual operation andis shown affixed to a wateriaucet.

Figure 2 is a longitudinal sectional view taken transversely of theheater shown in Figure 1.

Figure 3 is a sectional view of Figure 2 across theplane 3.- 3 thereof.

Figure 4 is asectional view of Figure2 across the plane 4-4 thereof.

vFigure 5 is a sectional view of the heater showing the-outer face ofone of the casing blocks in elevation and the electric circuitconductors se ur d thereto.

Figure 6 is a partial plan view of the inner face of the casing blockshown in Figure 5.

Figure 7 is an electric circuit diagram for the heater.

In accordance with the invention and the preferred form shown, numeralI0 indicates generally each of a pair of identical block members ofdielectric material such as porcelain or plastic adapted to abut and besecured to each other at the inner wall portions to form a water heatingchamber provided with live electric heating elements supported thereinand which is in contact with the water, and to further form insulatedwater or fluid inlet and outlet channels of such linear andcross-sectional dimensions to eliminate the communication ofobjectionable effects from derivative currents formed in the waterheating chamber to the source of fluid or Water supply and to thedischarged heated water. Each of the block numbers [6 is adapted tofurther form a second chamber for the mounting of a relay assembly tocontrol the energization of the electric heating elements in directcontact with the water or fluid within the heating chamber duri gfluidflow through the device.

Thus, each of the blocks ill at the inner wall has spaced recesses H andI2 to form water heating and relay Chambers, and a peripheral channelgenerally designated by numeral l3 to form respectively a water inletand a water outlet, both being in communication with the water heatingchamber. Channel l3 has a vertical leg l4 leading from an .openingMawhich penetrates the bottom of each block I 0 and proceed adjacent .tothe top to form a sinuous horizontal portion having legs 15, I6 and I!and a down.-

wardly extending vertical leg I8 which terminates in communication withrecess I2 as indicated by numeral I9. Each of blocks I6 between recessII and channel leg I4 is provided with openings 28 for securing theblocks together as by means of securing screws or bolts a. The blocksare further secured together at the outer and lower reduced ends 2Ithrough openings 22 by suitable securing means such as bolts 23.

A cover or plate of dielectric material 24 is provided for afiixation tothe inner wall of each of blocks I0 and has cut-outs 25 and 2-6 toregister with the recesses II and I2 respectively, the cover plateserving to form the outer wall of each of the channels I3. Suitablepacking is provided for waterproofing each of the channels I3 of blocksI6 as well as for waterproofing the peripheries of water and relaychambers II and I2. Additional packing 21 is provided between plates 24when the blocks are secured together to L maintain the water chamberwater-tight.

In the water heating chamber formed between the recesses I2 of blocks IDare the exposed or live electric heating elements in direct contact withthe water or fluid contents. This takes the form of electrodes betweenwhich a current passes either electrolyticallyor by means of aresistance element. However, as shown a disc or core 28 of dielectricmaterial having spaced openings 28a and 28b for water circulationtherethrough and having an'attaching bracket 29 for afiixation to theinner wall of recess I2 of one of the block members by suitable meanssuch'as bolts and nuts 30 and 30a at gaskets 3| has'a heating element orcoil 32 wound therearound. The ends of said coil are secured to theinner ends of bolts 30 and 38a which serve as exposed and liveelectrodes, the outer ends of said bolts on the outer wall of said blockI0 being adapted to serve as terminals for electric circuit connections.Disc 28 is adapted to extend into the opposite recess I2 of the opposingblock as best shown in Figures 2 and 3.

As controlling means for the energization of coil 32 there is provided apair of electrodes electrolytically operated by water flowingtherebetween in series circuit relation with a pressure switch. Thus,and as shown in Figures 2 and 6, a metallic plate 33 is mounted on theupper wall of channel leg I1 of one of the blocks hereinafter designatedas outlet'block II] as by a bracket and bolt 34 and a similar metallicplate 35 is mounted oppositely on the lower wall of said channel leg asby a bracket and bolt 36. Channel I3 of outlet block I0 serves as thefluid or water outlet channel hereinafter so designated while thechannel of the opposite block serves as the water inlet channelhereinafter so designated. The leg I1 of outlet channel I3 is broaderand deeper than legs I4, l5 and I6 for properly spacing the electrodes33 and 35 and effectively acting as an electrode chamber, and thevertical leg I8 may be broader than vertical leg I4. The correspondinglegs of the channel I3 of the inlet block II] are similarly dimensioned.Thus, water flows in the outlet channel from the water chamber ofrecesses I2 and proceeds through broad leg I8 at the mouth I9, theelectrode chamber or leg II, narrower and shallower legs I6 and I5 andfinally through the restricted leg I4 to the discharge I4a.

Similarly the inlet block III has the inlet channel I3 wherein the inletI4a at the water supply communicates with legs I4, I5, I6, I1 and I8(Figure 4) through mouth I9 into the water chamber. By virtue of suchreduced dimensions or length of the channels in both blocks, derivativecurrents having objectionable effects from the water heating chamberformed from recesses I2 and the electrode chamber or leg H are notcommunicated to the water source and to the discharged and heated waterbecause the flow of fluid or water in such restricted insulated channelsper se offers ohmic resistance and serves as eifective resistors toeliminate shocks or other objectionable eifects.

In leg I? of outlet block I0 is an orifice 3? penetrating the said blockand opening against a resilient diaphragm such as a rubber disc 38having a central and an electrical contact 39 on the opposite side, thesaid diaphragm being mounted against the outer wall of the block memberby a diaphragm frame 40. Frame 49 has a central electrical contact 4Ioppositely spaced from contact 39, the contact 4I having a terminal 42on the outside of the diaphragm frame. Bolts 34 and 36 conductivelyconnected to electrodes 33 and 35 respectively terminate on the outsideof diaphragm frame 40 as shown in Figure 5 to form terminals tofacilitate electrical connections as will hereinafter appear.

A relay assembly comprised of a circuit breaker and a winding tointerrupt relay contacts is mounted as shown in recess I I of the outletblock and extends into the recess of the opposite inlet block. Thewinding or coil generally designated by numeral 43 is supportedon abracket 44 while an armature 45 carries an interrupter relay contact 46at bridge 41. The second interrupting relay contact 48 is at the end ofa conducting spring 49, the other end of said spring being secured tothe top of bracket 44 by means of insulating plates 50, the said springpassing through bridge 41. Armature 45 penetrates and pivots on thevertical leg of bracket 44 and has the inner end attached to one end ofa spring 5I, the opposite end of spring 5I being anchored to bracket 44as at 52. to the outlet block I0 by'means of a conducting stud 53 whichterminates in a terminal 54 which penetrates the rear wall of recess I Iin the outlet block as best shown in Figure 2. Terminal 54 as will beshown hereafter in the electric circuit diagram of Figure 7 is connectedto one end of coil 43 and to relay contact 46.

An opening I05 opposite recess I I in the outlet block III permits acircuit conductor I84 con nected to conductor spring 49 of relay contact48 to penetrate block I0 for electrical connections. while numeral 56 atwasher indicates the iron core of coil 43 to magnetically draw and disengage armature 45 in the conventional manner.

To prevent fusing, sparking and oscillation between the relay contacts46 and 48 due to changes in water conductivity between the electrodes 33and 35 in the outlet block I0, as will hereinafter appear, there isprovided a defiectable nipple obstruction in the path of thespring-urged armature 45. The deflectable nipple obstruction comprises aresilient arm 5'! mounted on bracket 44 and carrying a nipple 58. Byusing such deflectable nipple, armature 45 must first deflect theposition of the spring and nipple to engage core 56. It is only for apre-determined maximum current flow through coil 43 that the position ofdeflect able nipple 58 is overcome for electrical engage-= ment betweenrelay contacts 46 and 48. And similarly armature 45 remains in contactwith iron core 53 to cause current flow through the heating coil 32until a pre-determined minimum flow of current goes through coil 43 atwhich time Bracket 44 is attached the 'force of the armature spring 5|frees armature 45 by deflecting nipple obstruction 58 to break the :flowof current through the heating coil 32 as will hereinafter appear.

In inlet block and on the outer wall thereof opposite leg ll of theinlet channel 13 is a clip 59 secured by a nut andbolt 58 passingthrough leg 11, the said clip serving to relieve strain on the powersupply line 55 passing therethrough for furnishing electrical energy forthe heating device. An electric bulb 6| is supported by circuitconductors on the outlet block l0 and is adapted to be energized whenthe heating element 32 is in operation as will hereinafter appear.

The inlet and outlet blocks I8 secured together as described and havingmounted therein the relay assembly in cooperating chambers ll,-theresistance element 32 in cooperating chambers 12, the electrodes 33 and35 and the pressure switch in the outlet channel I 3, and the externallymounted light bulb Bl constitute the integrated body of the heatingdevice wherein opening 14a of the inlet block Iii constitutes the inletchannel mouth and the aligned and opposite opening Ma of the outletblock constitutes the outlet channel discharge. This integrated body hasno exposed walls in conductive communication with the water flow in thefluid path of channels I 3 and recesses l2 and is also protected at theinlet channel mouth I 4a and at the outl t channel discharge l iaagainst communication of derivative currents from the water heatingchamber and the electrode leg or chamber I! by the resistoracting fluidflow in the inlet and outlet channels [3.

An adapter member for connecting the source of water of fluid supplysuch as from the spout of a faucet to the inlet channel mouth Ma ofinlet block l0 and for connecting the outlet channel discharge Ma ofoutlet block Iii to the adapter discharge end is provided and as shownconstitutes a supporting base for the integrated body of the heatingdevice. This adapter base preferably of dielectric material andindicated by numeral 63 also serves as a mounting for and cooperateswith an upper casing member also preferably of dielectric material suchas 62 to form a spaced outer iacket for the body. Adapter base 63 issubstantially cylindrical and has a rounded bottom wall and an uppersupporting edge 63a for the opposing lower edge of casing member 62which is shown in the form of a cylindrical shell provided with asubstantially semi-spherical top. On-the rear side of the top of casing52 is an opening covered by an insulated ring 64 throu h which the powerline connected to an electric plug 66 passes, and on the opposite sideis an opening opposite bulb 6! for viewing a light signal when thedevice is in operation. The light opening as shown and at the undersidehas a colored transparent member such as glass 5'! and at the u per sidehas a transparent or translucent panel 68.

The supporting edge 63a of the adapter base 63 and the opposite edge ofcasing 62 are each provided with a plurality of extensions inwardly ofthe diameters thereof at preselected angles,

said extensions being in alignment and proceeding downwardly andupwardly respectively from the edge 63d of the adapter base 63 and thelower edge of the casing 62. Said extensions are shown on Figures 1 and3 only in connection with adapter'base 63 and are each indicated bynumeral 69.

The extensions 69 of adapter base 63 are each provided with orifices I9and are excavated from theqouter .walls as indicated by verticalsocketsH to support the heads of screws 12 which penetrate said extensionsthrough orifices I0 and the corresponding extensions in the upper casing62 for demountably securing the jacket parts together.

The aligned extensions 69 in adapter base 63 and in casing 62 engage theouter wall portions of the blocks I0 against rotation as best shown inFigure 3. For this purpose the blocks ID at the outer walls and when inattached position are polygonal in form so that selected wall portionsare engaged by the extensions 69 of the casing 52 and adapter base 63.

Adapter base 63 is intended to provide a forward orifice I3 throughwhich a resilient discharge outlet 14 penetrates and which is connectedto the outlet channel discharge Ida The discharge outlet M as shown isin the form of an obliquely formed cup having a horizontal top wallportion 15 and a vertically directed lower wall portion 15, both of saidwalls extending from a neck 18 having an attaching flange I9 forengagement with the outlet channel discharge Ma as by a securing ring80. The mouth of cup 14 is provided with a channelled bead l1 disposedin an oblique plane and situated adjacent the edges of orifice 73.Engaged with the channel in head 11 of cup 14 is a sprayer member 8ihaving an engaging flange 82, the lower edge of the body of said sprayermember tapering rearwardly to provide an obliquely disposed andperforated bottom wall 83 through which heated water from the cup 14emerges in a spray. Cup 8] is capable of being ejected from bead ll whenthe openings in the bottom wall 83 become clogged by either water orsteam pressure. Moreover the body comprised of blocks Iii may be removedfrom adapter base 63 by first detaching the sprayer member 8| from beadTI and thereafter compressing resilient or rubber cup 14 secured to theoutlet panel discharge l ia on inward withdrawal from orifice l3.

Adapter base 53 further provides a coupling means for the spout of awater faucet and a delivery channel to the inlet channel mouth I la ofinlet block 10. The coupling means and delivery channel are formed inthe adapter base rearwardly of orifice 13 by means of a lug extension84. Thus, the lug extension 84 is provided with a vertical channel 85which is in communication with a horizontal channel leg 88 terminatingagainst a gasket 8! surrounding and secured to the inlet channel mouth14a of inlet block it). The shoulder 88 is formed at the end of channelleg 86 to support the shoulder of inlet block Iii adjacent the reducedlower portion 2 I as best shown in Figure 2. Shoulder 38 in combinationwith extensions 69 prevent rotary, tilting and vertical movement of thebody comprised of blocks IEI within the jacket formed by casing 62 andadapter base 53 without resorting to attaching means.

-'Ihemouth of vertical channel 85 is provided with a seat 89 to supporta diaphragm 93 having an orifice Si in an off-central position (Figure3). Diaphragm 98 is secured in seat 89 by means of a ring member 92having as shown a depressed segment 93 at the ring end. Ring member 92including portion 93 is secured over diaphragm conventionally as byscrews 94 and is provided with a thumb screw 98 which penetrates saidring member and which is directed toward and between a pair of spacedjaw points 95 adjacent opening 9|. As shown thumb screw 96, diaphragmorifice 9| and spaced jaw points 95 lie parallel with the transverseaxis of the heating device. The shank of a spout is adapted to besupported on depressed ring segment 93 while the side walls of the spoutare secured between the inner walls of ring 92, adjustable thumb screw96 and jaw points 95. This means of coupling the spout of a faucet iselastic for various sizes and shapes of spouts and spout shanks andinsures alignment between the off-center diaphragm orifice 9I and thespout mouth. The diaphragm 90 serves as a gasket between the spout mouthand the diaphragm orifice 9 I. l The jacket of wthe integrated bodycomprised of blocks It} as shown is provided with decorative means suchas aligned ribs 91 and 99 on casing 62 and adapter base 63 and a recesson the outer wall of rib 91 for the introduction of a name plate. Thesedecorative features are shown in Figure 1 which also illustrates inphantom a water faucet The electrical connections are shown in Figures 5and 7. Figure 5 shows the conductors of three electric circuits inparallel across the power terminals on the outside of outlet block I9,while the electric circuits themselves are shown in Figure '7. I

The first circuit comprises a circuit breaker having the winding 43which is eifective to open interrupting relay contacts 46 and 48 upondeenergization of coil 43. The winding or coil 43 is connected acrossthe terminals of the power supply in series circuit relation to thespaced electrodes 33 and 35 and to the diaphragm contacts 39 and4I.Thus, one end of relay coil 43 has a circuit conductor I01 leading todiaphragm frame contact M as at terminal 42, circuit conductor 38 leadsfrom diaphragm contact 39 to the terminal 36 of electrode plate 35,conductor I99 leads from the terminal 34 of electrode plate 33 to oneterminal of the power source. The other end of relay coil 43 as atterminal 54 (which is also the terminal for relay contact 46) isconnected by conductor I02 to the other terminal of the power source.

The circuit of electric bulb GI and series re-- sistor I08 lies acrossthe power terminals in series with the interrupting relay contacts 46and 43. Thus, circuit conductor I02 leads from one terminal of the powersupply to terminal 54 of relay contact 46, circuit conductor I04 leadsfrom the second relay contact 48 to one terminal 30a of resistanceelement 32, circuit conductor I03 containing a series resistor I08 leadsfrom terminal 30a to bulb 6|, and circuit conductor I06 proceeds frombulb BI and leads through con ductor I09 to conductor IOI which isconnected to the other terminal of the power supply.

The circuit of the heating element 32 is connected across the terminalsof the power source in series circuit relation with the interruptingrelay contacts 46 and 48. Thus, circuit conductor "II from one terminalof the power source leads to one terminal 30 of resistance element 32,circuit conductor I04 leads from the other terminal 30a of theresistance element to the relay contact 48, and circuit conductor I02leads from terminal 54 of relay contact 46 to the other terminal of thepower source.

From the foregoing description of the heating device it may be seen thatfluid or water in the water heating chamber formed from recesses I2 atall times submerges resistance coil 32 during current flow to preventoverheating. There is a tortuous constricted flow of water from thefaucet through the insulated and narrow inlet channel I3 of inlet blockI0 to the top of the water heating chamber and a similar outflow path inthe outlet channel I3 of the outlet block I0 from the top of the waterheating chamber to the discharge end or sprayer member of the adapterbase 63. The channels I3 of each of the blocks IU control the output perunit time of the water flowing through the integrated bodv formed fromthe said blocks. The flow of water through each of the restricted andinsulated channels I3 by virtue of the dimensions of said channelspractically reduces the communication of derivative currents in thewater of the water heating chamber which is exposed to the liveelectrical elements to the discharged hot water and to the faucetitself.

The handle of faucet I00 functions for volume control and the supply ofboth water and predetermined Water pressure in the fluid path of theblocks comprised of channels I3 and water chamber I2 closes a powercircuit through the resistance element 32. The degree of opening or turnof the faucet handle controls the temperature of the water dischargedfrom the device. When the handle is partly turned, the water will issuealmost boiling; when half turned the water will issue hot and when fullyturned will issue warm. The handle of the faucet I00 may thus beconsidered as a temperature control.

Electrodes 33 and 35 in the fluid path and as shown in outlet channel I3are adapted to close the interrupting contacts of the relay assemblywhen the gap between the electrodes is electrically closed by 11116presence of water. When the relay contacts 45 and 48 are closed by theintervention 01' water, current should go through the resistance coil 32from the power source. However, for safety purposes there is provided inelectric circuit series with the electrodes 33 and 35 a pressure switchwherein the diaphragm 38 thereof also is in the fluid path andpreferably in communication with leg I? of outlet channel I3 so that inthe event the gap between the electrodes is closed by water but in theabsence of predetermined pressure flow, the resistance element 32 willnot be energized. When the resistance element 32 is energized the pilotlight BI is on to incncate to the consumer that the device is inoperation.

It is to be noted that the total area of the openings in the sprayerplate 83 is controlled to allow sui'ficient time exposure of the waterwithin the water heating chamber for heat absorption as are thedimensions in the fluid path in blocks I0 to create a predeterminedpressure to operate the pressure switch.

In operation the handle of faucet I 00 is opened for water flow throughthe bod I0. Water flows through diaphragm opening 9I into channels 85,86, inlet channel mouth I4a, legs I4, I5, I6, I! and E8 of inlet channelI3 and through mouth I9 into the water heating chamber and from mouth I9of the outlet channel I3 through the legs I8, I1, I6, I5, I4 and outletchannel discharge I4a through cup I4 and out of sprayer plate 83. Whenthe water is turned on, the water heating chamber after a certain lapseof time, is filled with water which submerges the resistance element 32and thereafter overflows through the outlet channel discharge I 4a andthrough cup I4 and sprayer plate 83. As soon as the gap betweenelectrodes 33 and 35 in the leg I! of outlet channel I3 is filled by awater flow the pressure of which closes the contacts 39 and M of thepressure switch, the water conductivityand the pressure from the" waterflow closes" the"; power circuit across theresistance element 32.

When the faucet handle is turned to complete off -position, no morewater momentarily will pass through sprayer plate 83. However, thedevice will remain full and the stored" water within the water heatingchamber will'not be further heated because of the resultantopening ofthepressure switch contacts 39 and 4|. If the'flow of waterort'empe-rature thereof through thedevice is'below the minimum requiredto. absorb the heat developed by the resistance element 32, the waterwill boil and the steam created will force the water out oithe outle'tchannel 13 and open the electrode gap until morewater passes through theoutletchannel [3 to closesaid electrode gap. Of

course the gap between the electrodes remains open in the presence ofwater vapor and steam pressure, but the pressure switch is closed onlywhen there is suflicient water flow or steam pressure in outlet channell3. Consequently, when the wateris turned off-no current flows throughthe resistance element in the water heating chamber. Because theresistance element'32 is below the top of the water heatin chamber asshown, current therethrough will be out off while the element iscompletely submerged in the water.

When water starts to flow in the leg ll of the electrode chamber havingelectrode plates 33 and 35, the gap between-said plates is invadedgradually. The water thus acts as a rheostat in the circuit. Theconsequent progressive increase in voltage may cause flickering betweencontacts 46 and 48 due to the alterations of the current. Therefore,tc-prevent fusing and sparking between the circuit interrupting contacts45 and 48, the deflectable nipple 58 is provided to serve as anobstruction inthe path of the spring-urged armature 45'so that thearmature has to force nipple 58 out of its path toengage the energizedcore 56. This takes place onlyat a predetermined maximum'current flowthrough the relay coil 43.

And similarly the armature 45 remains in contact with the energized core56 to cause current flow through the resistance element 32 until apredetermined minimum flow of current passes through the relay coil 43at which time the force i of the armature spring 5| frees armature 45 bydeflecting the nipple obstruction 58 to break the flow of currentthrough the resistance element 32.

The heating device above described may be considered as an automaticinstant heater attach able to a faucet and which is small, safe,compact, easily assembled and dismantled, and characterized for its highefliciency, sure performance, length of life and simplicity.

I wish it understood that other fluids having similar conductivityproperties as Water may be heated by the device described and that minorchanges and variations in the material, location, integration, size andshape of parts may all be resorted to without departing from the spiritof the invention and the scope of the appended claims.

I claim:

1. In an electric water heater, a body having an internal insulatedfluid chamber, exposed electric heating elements in said chamber, afluid path for said chamber and through said body comprisingelectrically non-conducting restricted channels of preselecteddimensions formed in said body and leading into and out of said fluidchamber so that fluid flow through said restricted channels ohmicallyresists communication of effective derivative currents from the chamberand formed therein by iii contact: between the fluid and the heatingelement, and circuit controlling means in one of said channels andcomprising a pair of spaced electrodes and a pressure switch in serieselectric circuit, the said electrodes being adapted to be electricallyclosed by and when intervened by Water and the pressure switch beingadapted to be electrically closed when there is fluid flow atpredetermined pressure.

2. In an electric water heater, a pair of blocks adapted for oppositeengagement and each having cooperating recesses to form an insulatedfluid chamber, exposed electric heating. elements in said fluid chamber,each of said blocks having formed therein electrically non-conductingrestricted channels of preselected dimensions to form a fluid paththrough said blocks with said fluid container so that the fluid flow insaid restricted channels ohmically resists communication of derivativecurrents from the chamber and formed therein by contact between thefluid and the heatin elements, and circuit controlling means in one ofsaid channels and comprisinga pair of spaced electrodes and apressureswitch in series electric circuit, the said electrodes beingadapted to be electrically closed by and whenintervened by water andthepressure switch being adapted to be electrically closed when there isfluid flow at predetermined-pressure.

3. In an electric Water heater, a body having an internal insulatedfluid chamber, exposed electric heating elements in said chamber, afluid path through said body communicating with the fluid chamberadjacent the top thereof and compris in'g electrically non-conductingrestricted channels of preselected dimensions formed in the body soth'atthe fluid flow in said-channels ohmically resists communication ofeffective derivativecurrents from the chamber and formed therein bycontact between the fluid and the heating ele ments, and circuitcontrolling means in one of said channelsan'd com'p'r'isinga pair ofspaced electrodesandapressure switch in series electric cir cuit, thesaid electrodes being adapted to be electrically closed by and whenintervened by water and the pressure switch being adapted to beelectrically closed when there is fluid flow at predetermined pressure.

4. In an electric water heater, a body having an insulated internalfluid chamber, exposed electric heating elements along the bottom ofsaid chamber, a fluid path through said bodyv communicating with thefluid chamber adjacent the top thereof and comprising an electricallynonconducting restricted inlet channel and an electricallynon-conducting restricted outlet channel, the channel being ofpreselected dimensions so that the fluid flow in said channels ohmicallyresists communication of eflective derivative currents from the chamberand formed therein by contact between the fluid and the heatingelements, and circuit controlling means in the outlet channel andcomprising a pair of spaced electrodes adapted to be electrically closedby and when intervened by water, and a pressure switch in serieselectric circuit with said electrodes disposed in the fluid path andbeing adapted to be electrically closed when there is fluid flow atpre-- determined pressure.

5. In an electric water heater, 9, body having an insulated internalfluid chamber, exposed electric heating elements in said chamber, afluid path through said body communicating with the fluid chamber ndcomprising an electrically nonconducting restricted inlet channel and anelecii trically non-conducting restricted outlet channel, the channelsbeing of preselected dimensions so that the fluid flow in said channelsohmically resists communication of efiective derivative currents fromthe chamber and formed therein by contact between the fluid and theheating elements, and circuit controlling means in the fluid pathcomprising a pair of spaced electrodes and a pressure switch in serieselectric circuit, the said electrodes being adapted to be electricallyclosed by and when intervened by water and the pressure switch beingadapted to be electrically closed when there is fluid flow atpredetermined pressure.

6. In an electric water heater, a body having an insulated internalfluid chamber, exposed electric heating elements in said chamber, afluid path through said body communicating with the circuit, the saidelectrodes being adapted to be electrically closed by and whenintervened by water and the pressure switch being adapted to beelectrically closed when there is fluid flow at predetermined pressure.

'7. In an electric water heater, a fluid chamber.

exposed electric heating elements in said chamber, inlet and outletpaths through and in the ,walls of said chamber to form a fluid paththerewith and comprising electrically non-conducting restricted channelsof preselected dimensions 40 formed in the walls of said chamber so thatthe fluid flow through said restricted channels ohmically resistscommunication of efiective deriva- 12 tive currents from the chamber andformed therein by contact between the fluid and the heating elements,and circuit controlling means in the fluid and the heating elements, andcircuit controlling means in the fluid path comprising a pair ofelectrodes and a pressure switch in series electric circuit adapted tobe electrically closed respectively by and when intervened by water andby predetermined fluid flow pressure.

8. In an electric water heater, a fluid chamber having heatingelectrodes therein, an inlet and an outlet of restricted dimensions toohm ically resist communication of derivative currents in communicationwith said fluid chamber and forming a fluid path therewith, and circuitcontrolling means in the fluid path comprising a pair of electrodes anda pressure switch in series electric circuit adapted to be electricallyclosed respectively by and when intervened by water and-by predeterminedfluid flow pressure.

9. In an electric water heater, a fluid chamber having heatingelectrodes therein, a second fluid chamber in communication therewith,and circuit controlling means in said second chamber comprising a pairof electrodes and a pressure switch in series electric circuit adaptedto be electrically closed respectively by and when intervened by waterand by predetermined fluid flow pressure.

GERALD C. WICKS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,561,243 Keene Nov. 10, 19251,999,962 Des Rosiers Apr. 30, 1935 2,032,210 Holt Feb. 25, 19362,380,132 Walther July 10, 1945 2,400,618 Wicks May 21, 1946

